The sacraments are outward and visible signs of inward and spiritual grace, given by Christ as sure and certain means by which we revie that grace.
Grace is God's favor towards us, unearned and undeserved; by grace God forgives our sins, enlightens our minds, stirs our hearts, and strengthens our wills.
The two great sacraments given by Christ to his Church are Holy Baptism and the Holy Eucharist.
Other sacramental rites which evolved in the Church include confirmation, ordination, holy matrimony, reconciliation of a penitent, and unction (anointing of the sick).
Although they are means of grace, they are not necessary for all persons in the same wat that Baptism and Eucharist are.
The Book of Common Prayer p.857-858, 860